SENSORS IN M272

M 272 ENGINEhistoryIntroduced in 2004Based on theM112V6introduced in 1998.3.5 litre V6 develops a peak power of 200kW (272hp) at 6000 rpm and torque of 350Nm from 2500 5000 rpm.87 per cent of this peak torque is available from just 1500 rpmDeveloped at the Stuttgart-Unterturkheim facilities where a team of around 500 engineers, technicians and mechanics developed the new design. Approximately 400 prototype engines were built for testingObjectivesThe key development objectives for the engine were:Power outputTorque outputFuel consumptionComfortExhaust emissionsNew design include variable camshaft timing, a two-stage intake manifold, tumble flaps, heat management and lightweight engineSPECIFICATIONE25Displacement - 2.5L (2496cc) Bore dimension - 88mm Stroke - 68.4mm Output - 201 hp (150kW) @ 6100rpm Torque - 245Nm @ 2900-5500rpm.SPECIFICATIONE30Displacement - 3.0L (2996cc) Bore dimension - 88mm Stroke - 82mm Output - 228hp (170kW) @ 6000rpm Torque - 300Nm @2500-5000rpm

SPECIFICATIONE35Displacement - 3.5L (3498cc) Bore dimension - 92.6mm Stroke - 86mmOutput - 268hp(200kW) @ 6000rpmTorque - 350Nm @ 3500rpmSPECIFICATIONCGI VariantDirect injected variant introduced in 2006 Stratified-Charged Gasoline Injection (CGI). Output -288hp(215kW) Torque - 365Nm

SPECIFICATIONNon CGIUpdate to non-CGI in 2008.Output - 232kW @ 6500rpm Torque - 360Nm @ 4900rpm. Rev-limit raised to 7200rpm, increase in compression ratio and modifications to the valve train.

COMPARISON268 hp @ 6000 rpm 349 Nm @ 2500 to 5000 rpmCompression Ratio 10.7 : 1Sparkplugs per cylinder 1ME 9.7Coil On Plug214 hp @ 5700 rpm 309 Nm @ 5700 rpmCompression Ratio 10.0 : 1Sparkplugs per cylinder 2ME 2.8Double ignition coilsM2723.5 litreM1123.2 litreCOMPARISON

FEATURES90 degree V6 configurationLighter engines componentsAluminum crank case and iron coated pistonsLighter one piece crankshaft

Forged steel connecting rodsCounter rotating balance shaftSilicon /aluminum lined cylindersMagnesium intake manifolds.4 valves per cylinder and DOHC

Continuous VVT on both intake and exhaust camshaftsNickel coated high strength exhaust valves40 advanced for intake (from 4 BTDC to up to 36 ATDC) 40 retard for exhaust (from 30 BTDC to up to 10 ATDC)4 hall effect sensors, capable of detecting cam position during stationary.

VARIABLE LENGTH INTAKE MANIFOLD

Magnesium intake manifold with integrated vacuum reservoirVariable intake runnerShort runner for higher RPMLong runner for lower RPM

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Engine load over 50% from approx. 1750 RPM intake flaps closed (long runner)Above 3900 RPM switchover solenoid deactivated via ME intake flaps open (short runner)

Swirl-Flaps also added providing better fuel mixtureIntake air is swirled via swirl flap for improved mixture processVacuum diaphragm driven by ME controls flap positionSwirl flap position sensors (hall sensors) located at rear of intake manifold

Individual coil on plugDriver located inside coil not in ME 9.7Each coil controlled separatelyDiagnostic information sent back to MEBi-directional communication with MEIGNITION COILME CONTROLLED THERMOSTATCoolant Temperature is regulated via Me 9.73 plate thermostatRegulates temperature from 185F to 221F (85C to 105C)4 operating modes dependent on engine temperature and loadImproved engine warm-up and optimum control of engine temperature SENSORS IN M272Camshaft Hall SensorLocated at the front of the cylinder head in front of respective camshaftDetect the camshaft position in a contactless manner using pulse wheel on camshaftEnsures camshaft position even at engine offReduces exhaust emission and ensures optimal injection quantityCrankshaft Hall SensorBehind the left cylinder bank on the transmission flangeDetects position and rotational speed of the crankshaft in a contactless manner using incremental wheel of perforated plateKnock SensorLocated under the variable intake manifold on crankcaseDetects vibrations on crankcase for knock controlVibration converted by internally mounted piezoelectric material to electrical signal

Coolant Temperature SensorLocated at the rear of left cylinder headDetect coolant temperature and produce corresponding voltageUses a negative temperature coefficient resistorIntake Manifold Tumble Flap Position SensorLocated at rear end of variable intake manifold above tumble flap shaftDetect the manual end positions of tumble flap shafts

Hot Film Mass Air Flow SensorLocated behind the variable intake manifoldDetect mass flow rate of air and temperature at intakeElectronically regulates the MAF using changeable voltage at heating resistorIntake Manifold Pressure SensorLocated above the left cylinder head Detects the absolute pressure at the variable intake manifoldIntake manifold pressure deforms a membrane which acts on a potentiometer

Oxygen SensorDownstream of catalytic converterScrewed on to the side of firewall catalytic converterDetects the residual oxygen content in exhaust gas from catalytic convertorConsists of the sensor element (Nernst concentration cell)Upstream of catalytic converterScrewed on to upstream of firewall catalytic converterDetects the residual oxygen content in exhaust gas to catalytic convertorConsists of the sensor element (Nernst concentration cell with O2 pump cell)

Fuel Pressure sensorLocated above the left closing plate of the fuel tankDetect fuel pressure for injection systemIt uses a membrane which deforms by fuel pressure which acts on a potentiometer changing resistance

Accelerator pedal sensorLocated behind accelerator pedal moduleCoverts mechanical movement of accelerator pedal into electrical voltageConsists of rotating ring magnet in a printed circuit board

VEHICLES USING 272 ENGINES2004- 2010:C 230 (E25)SLK 350 (E35)CLS 350 (E35)E 230 (E25)

2005- 2010:CLS 280 (E30)CLK 280 (E30)C 280 (E30)E 280 (E30)SL 280 (E30)C 350 (E35)E 350 (E35)S 350 (E35)SL 350 (E35)Viano (E35)2006-2010:R 280 (E30)R 350 (E35)ML 250 (E35)Sprinter (E35)2007-2010:S 280 (E30)2008-2010:CLC 230 (E25)CLC 350 (E35)

ENGINE DIAGNOSTICSCompression TestPressure in the cylinder checked by a compression gaugePressure is indicated in pounds per square inch(psi) or metric kilopascals(kPa)Wet compression test allows you to identify if it is caused by worn or damaged piston rings

Cylinder Leakage TestTo measure the percentage of compression lost and to help locate the source of leakageApplies compressed air to a cylinder through the spark plug holeGauge registers the percentage of air pressure lost when the compressed air is applied to the cylinder, typically reads 0% to 100%Cylinder Power Balance TestUsed to check if all of the engines cylinders are producing the same amount of powerEach cylinder is disabled, one at a time, and the change in engine speed is recordedIf all of the cylinders are producing the same amount of power, engine speed will drop the same amount as each cylinder is disabled

Vacuum TestManifold vacuum is tested with a vacuum gauge, the gauges hose is connected to a vacuum fitting on the intake manifoldThe intensity of the fluctuation indicates the severity of the problemconclusion Perhaps the most impressive aspect of the engine is its ability to provide such a wide and high torque plateau with an excellent specific power figure. That combination should make for a very drivable design that also retains plenty of punch when the throttle is floored.